>>30783836No, but our Tournaments, which are what award Master Balls capable of catching legends/mythicals, do go by Smogon rules. So Maple's Aegislash is banned from Singles tourneys, but not dubs/trips, and certainly not quests.
Other than that, all legendaries are banned from the start, and 670BST+ legendaries cannot be caught at all as far as our rules go presently. Hoopa and Celebi are also no-go because of the extent of their canon powers, and the Tapus (as much as I hate to say it) are out unless we can find a damn good excuse as to why they are somewhere besides Alola.